diff --git a/java/src/com/android/inputmethod/keyboard/Key.java b/java/src/com/android/inputmethod/keyboard/Key.java
index 24e8926..15259a2 100644
--- a/java/src/com/android/inputmethod/keyboard/Key.java
+++ b/java/src/com/android/inputmethod/keyboard/Key.java
@@ -267,7 +267,7 @@
     }
 
     private static boolean isDigitPopupCharacter(CharSequence label) {
-        return label.length() == 1 && Character.isDigit(label.charAt(0));
+        return label != null && label.length() == 1 && Character.isDigit(label.charAt(0));
     }
 
     private static CharSequence[] filterOutDigitPopupCharacters(CharSequence[] popupCharacters) {